The expression “chamber unit” generally references a hollow body, known as chamber or drip, which is used in hemodialysis lines or other circuits in medical applications and has the appearance of a body that is rendered monolithic and is constituted by two parts, particularly a body (which is capsule-like) and a lid (which is flange-shaped), which are mutually assembled and sealed.
Each one of the two parts can comprise one or more tubular connectors, which are formed inside the chamber and are connected to the outside of such chamber by means of inlet and outlet ports that are adapted to be connected to the blood circuit; therefore, the chamber unit is designed to be mated with a tube that leads to a hemodialysis line or to a patient.
In particular, the chamber unit is connected in output and in input by means of connections of a known type, such as of a conical type or by adhesive bonding, to the blood circuit tube.
Moreover, it is possible to provide further connections, in a variable number and arrangement, in input and in output with respect to the chamber unit, for example controlled by auxiliary tubes such as the pressure measurement line, lines for withdrawing or administering drugs or other fluids required for therapy.
Known chamber units are usually made of thermoplastic material; the internal geometry of the chamber can have different shapes, studied to avoid the formation of clots and to ensure the correct inflow and outflow of blood and of the various fluids involved in the therapy.
The currently known methods for producing chamber units consist in forming the two parts, respectively the body and the lid, individually by injection-molding thermoplastic material, in superimposing the two parts to close the chamber body, and in sealing the parts in a monolithic body.
The formation of each one of the two parts occurs by using a respective mold; if the part to be formed has threads, particularly external ones, the corresponding female mold part is divided into at least two shells that can open in a radial direction with respect to the axis of the thread in order to allow the extraction of the formed part.
Various methods are known for sealing the two parts and include for example hot welding, ultrasound welding, adhesive bonding and overmolding of thermoplastic material at the joining point of the two parts.
Sealing by overmolding occurs by injection-molding thermoplastic material by using a mold constituted by two mold parts, in one of which there is a receptacle for one of the two parts to be sealed and in the other of which there is a receptacle for the other part, so that when the mold is closed the portions to be mutually sealed, respectively of the first and second parts formed previously, face each other.
In the two mold parts, at the joining line of the two parts, there is a female mold part for forming the sealing material to be overmolded.
Apparatuses for producing chamber units currently comprise molds for forming the individual parts to be assembled and mold for sealing them by overmolding, which are mutually separated and mutually independent and are mounted on respective separate presses.
These apparatuses for performing the known methods are riot free from drawbacks, which include the fact that they are structurally and constructively complex and bulky and difficult to manage, have a limited production rate and relatively high installation and operating costs, and this leads to a significant increase in the production times and costs of chamber units.
By way of example, it is in fact noted that known systems require the availability of large work areas to provide various stations for forming and sealing the parts, each station being provided with respective molds, presses and devices for gathering the individual or assembled parts, it being further necessary to transfer the parts from the forming stations to the sealing stations and arrange them in the sealing molds.